/*
 * Copyright 2012 The Netty Project
 *
 * The Netty Project licenses this file to you under the Apache License,
 * version 2.0 (the "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at:
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations
 * under the License.
 */
package io.netty.channel.epoll;

import io.netty.buffer.ByteBufAllocator;
import io.netty.channel.ChannelException;
import io.netty.channel.ChannelOption;
import io.netty.channel.FixedRecvByteBufAllocator;
import io.netty.channel.MessageSizeEstimator;
import io.netty.channel.RecvByteBufAllocator;
import io.netty.channel.WriteBufferWaterMark;
import io.netty.channel.socket.DatagramChannelConfig;

import java.io.IOException;
import java.net.InetAddress;
import java.net.NetworkInterface;
import java.util.Map;

public final class EpollDatagramChannelConfig extends EpollChannelConfig
        implements DatagramChannelConfig
{
    private static final RecvByteBufAllocator DEFAULT_RCVBUF_ALLOCATOR = new FixedRecvByteBufAllocator(
            2048);

    private final EpollDatagramChannel datagramChannel;

    private boolean activeOnOpen;

    EpollDatagramChannelConfig(EpollDatagramChannel channel)
    {
        super(channel);
        datagramChannel = channel;
        setRecvByteBufAllocator(DEFAULT_RCVBUF_ALLOCATOR);
    }

    @Override
    @SuppressWarnings("deprecation")
    public Map<ChannelOption<?>, Object> getOptions()
    {
        return getOptions(super.getOptions(), ChannelOption.SO_BROADCAST,
                ChannelOption.SO_RCVBUF, ChannelOption.SO_SNDBUF,
                ChannelOption.SO_REUSEADDR,
                ChannelOption.IP_MULTICAST_LOOP_DISABLED,
                ChannelOption.IP_MULTICAST_ADDR, ChannelOption.IP_MULTICAST_IF,
                ChannelOption.IP_MULTICAST_TTL, ChannelOption.IP_TOS,
                ChannelOption.DATAGRAM_CHANNEL_ACTIVE_ON_REGISTRATION,
                EpollChannelOption.SO_REUSEPORT);
    }

    @SuppressWarnings(
    { "unchecked", "deprecation" })
    @Override
    public <T> T getOption(ChannelOption<T> option)
    {
        if (option == ChannelOption.SO_BROADCAST)
        {
            return (T) Boolean.valueOf(isBroadcast());
        }
        if (option == ChannelOption.SO_RCVBUF)
        {
            return (T) Integer.valueOf(getReceiveBufferSize());
        }
        if (option == ChannelOption.SO_SNDBUF)
        {
            return (T) Integer.valueOf(getSendBufferSize());
        }
        if (option == ChannelOption.SO_REUSEADDR)
        {
            return (T) Boolean.valueOf(isReuseAddress());
        }
        if (option == ChannelOption.IP_MULTICAST_LOOP_DISABLED)
        {
            return (T) Boolean.valueOf(isLoopbackModeDisabled());
        }
        if (option == ChannelOption.IP_MULTICAST_ADDR)
        {
            return (T) getInterface();
        }
        if (option == ChannelOption.IP_MULTICAST_IF)
        {
            return (T) getNetworkInterface();
        }
        if (option == ChannelOption.IP_MULTICAST_TTL)
        {
            return (T) Integer.valueOf(getTimeToLive());
        }
        if (option == ChannelOption.IP_TOS)
        {
            return (T) Integer.valueOf(getTrafficClass());
        }
        if (option == ChannelOption.DATAGRAM_CHANNEL_ACTIVE_ON_REGISTRATION)
        {
            return (T) Boolean.valueOf(activeOnOpen);
        }
        if (option == EpollChannelOption.SO_REUSEPORT)
        {
            return (T) Boolean.valueOf(isReusePort());
        }
        return super.getOption(option);
    }

    @Override
    @SuppressWarnings("deprecation")
    public <T> boolean setOption(ChannelOption<T> option, T value)
    {
        validate(option, value);

        if (option == ChannelOption.SO_BROADCAST)
        {
            setBroadcast((Boolean) value);
        }
        else if (option == ChannelOption.SO_RCVBUF)
        {
            setReceiveBufferSize((Integer) value);
        }
        else if (option == ChannelOption.SO_SNDBUF)
        {
            setSendBufferSize((Integer) value);
        }
        else if (option == ChannelOption.SO_REUSEADDR)
        {
            setReuseAddress((Boolean) value);
        }
        else if (option == ChannelOption.IP_MULTICAST_LOOP_DISABLED)
        {
            setLoopbackModeDisabled((Boolean) value);
        }
        else if (option == ChannelOption.IP_MULTICAST_ADDR)
        {
            setInterface((InetAddress) value);
        }
        else if (option == ChannelOption.IP_MULTICAST_IF)
        {
            setNetworkInterface((NetworkInterface) value);
        }
        else if (option == ChannelOption.IP_MULTICAST_TTL)
        {
            setTimeToLive((Integer) value);
        }
        else if (option == ChannelOption.IP_TOS)
        {
            setTrafficClass((Integer) value);
        }
        else if (option == ChannelOption.DATAGRAM_CHANNEL_ACTIVE_ON_REGISTRATION)
        {
            setActiveOnOpen((Boolean) value);
        }
        else if (option == EpollChannelOption.SO_REUSEPORT)
        {
            setReusePort((Boolean) value);
        }
        else
        {
            return super.setOption(option, value);
        }

        return true;
    }

    private void setActiveOnOpen(boolean activeOnOpen)
    {
        if (channel.isRegistered())
        {
            throw new IllegalStateException(
                    "Can only changed before channel was registered");
        }
        this.activeOnOpen = activeOnOpen;
    }

    boolean getActiveOnOpen()
    {
        return activeOnOpen;
    }

    @Override
    public EpollDatagramChannelConfig setMessageSizeEstimator(
            MessageSizeEstimator estimator)
    {
        super.setMessageSizeEstimator(estimator);
        return this;
    }

    @Override
    @Deprecated
    public EpollDatagramChannelConfig setWriteBufferLowWaterMark(
            int writeBufferLowWaterMark)
    {
        super.setWriteBufferLowWaterMark(writeBufferLowWaterMark);
        return this;
    }

    @Override
    @Deprecated
    public EpollDatagramChannelConfig setWriteBufferHighWaterMark(
            int writeBufferHighWaterMark)
    {
        super.setWriteBufferHighWaterMark(writeBufferHighWaterMark);
        return this;
    }

    @Override
    public EpollDatagramChannelConfig setWriteBufferWaterMark(
            WriteBufferWaterMark writeBufferWaterMark)
    {
        super.setWriteBufferWaterMark(writeBufferWaterMark);
        return this;
    }

    @Override
    public EpollDatagramChannelConfig setAutoClose(boolean autoClose)
    {
        super.setAutoClose(autoClose);
        return this;
    }

    @Override
    public EpollDatagramChannelConfig setAutoRead(boolean autoRead)
    {
        super.setAutoRead(autoRead);
        return this;
    }

    @Override
    public EpollDatagramChannelConfig setRecvByteBufAllocator(
            RecvByteBufAllocator allocator)
    {
        super.setRecvByteBufAllocator(allocator);
        return this;
    }

    @Override
    public EpollDatagramChannelConfig setWriteSpinCount(int writeSpinCount)
    {
        super.setWriteSpinCount(writeSpinCount);
        return this;
    }

    @Override
    public EpollDatagramChannelConfig setAllocator(ByteBufAllocator allocator)
    {
        super.setAllocator(allocator);
        return this;
    }

    @Override
    public EpollDatagramChannelConfig setConnectTimeoutMillis(
            int connectTimeoutMillis)
    {
        super.setConnectTimeoutMillis(connectTimeoutMillis);
        return this;
    }

    @Override
    @Deprecated
    public EpollDatagramChannelConfig setMaxMessagesPerRead(
            int maxMessagesPerRead)
    {
        super.setMaxMessagesPerRead(maxMessagesPerRead);
        return this;
    }

    @Override
    public int getSendBufferSize()
    {
        try
        {
            return datagramChannel.fd().getSendBufferSize();
        }
        catch (IOException e)
        {
            throw new ChannelException(e);
        }
    }

    @Override
    public EpollDatagramChannelConfig setSendBufferSize(int sendBufferSize)
    {
        try
        {
            datagramChannel.fd().setSendBufferSize(sendBufferSize);
            return this;
        }
        catch (IOException e)
        {
            throw new ChannelException(e);
        }
    }

    @Override
    public int getReceiveBufferSize()
    {
        try
        {
            return datagramChannel.fd().getReceiveBufferSize();
        }
        catch (IOException e)
        {
            throw new ChannelException(e);
        }
    }

    @Override
    public EpollDatagramChannelConfig setReceiveBufferSize(
            int receiveBufferSize)
    {
        try
        {
            datagramChannel.fd().setReceiveBufferSize(receiveBufferSize);
            return this;
        }
        catch (IOException e)
        {
            throw new ChannelException(e);
        }
    }

    @Override
    public int getTrafficClass()
    {
        try
        {
            return Native.getTrafficClass(datagramChannel.fd().intValue());
        }
        catch (IOException e)
        {
            throw new ChannelException(e);
        }
    }

    @Override
    public EpollDatagramChannelConfig setTrafficClass(int trafficClass)
    {
        try
        {
            Native.setTrafficClass(datagramChannel.fd().intValue(),
                    trafficClass);
            return this;
        }
        catch (IOException e)
        {
            throw new ChannelException(e);
        }
    }

    @Override
    public boolean isReuseAddress()
    {
        try
        {
            return Native.isReuseAddress(datagramChannel.fd().intValue()) == 1;
        }
        catch (IOException e)
        {
            throw new ChannelException(e);
        }
    }

    @Override
    public EpollDatagramChannelConfig setReuseAddress(boolean reuseAddress)
    {
        try
        {
            Native.setReuseAddress(datagramChannel.fd().intValue(),
                    reuseAddress ? 1 : 0);
            return this;
        }
        catch (IOException e)
        {
            throw new ChannelException(e);
        }
    }

    @Override
    public boolean isBroadcast()
    {
        try
        {
            return Native.isBroadcast(datagramChannel.fd().intValue()) == 1;
        }
        catch (IOException e)
        {
            throw new ChannelException(e);
        }
    }

    @Override
    public EpollDatagramChannelConfig setBroadcast(boolean broadcast)
    {
        try
        {
            Native.setBroadcast(datagramChannel.fd().intValue(),
                    broadcast ? 1 : 0);
            return this;
        }
        catch (IOException e)
        {
            throw new ChannelException(e);
        }
    }

    @Override
    public boolean isLoopbackModeDisabled()
    {
        return false;
    }

    @Override
    public DatagramChannelConfig setLoopbackModeDisabled(
            boolean loopbackModeDisabled)
    {
        throw new UnsupportedOperationException("Multicast not supported");
    }

    @Override
    public int getTimeToLive()
    {
        return -1;
    }

    @Override
    public EpollDatagramChannelConfig setTimeToLive(int ttl)
    {
        throw new UnsupportedOperationException("Multicast not supported");
    }

    @Override
    public InetAddress getInterface()
    {
        return null;
    }

    @Override
    public EpollDatagramChannelConfig setInterface(InetAddress interfaceAddress)
    {
        throw new UnsupportedOperationException("Multicast not supported");
    }

    @Override
    public NetworkInterface getNetworkInterface()
    {
        return null;
    }

    @Override
    public EpollDatagramChannelConfig setNetworkInterface(
            NetworkInterface networkInterface)
    {
        throw new UnsupportedOperationException("Multicast not supported");
    }

    @Override
    public EpollDatagramChannelConfig setEpollMode(EpollMode mode)
    {
        super.setEpollMode(mode);
        return this;
    }

    /**
     * Returns {@code true} if the SO_REUSEPORT option is set.
     */
    public boolean isReusePort()
    {
        try
        {
            return Native.isReusePort(datagramChannel.fd().intValue()) == 1;
        }
        catch (IOException e)
        {
            throw new ChannelException(e);
        }
    }

    /**
     * Set the SO_REUSEPORT option on the underlying Channel. This will allow to
     * bind multiple {@link EpollSocketChannel}s to the same port and so accept
     * connections with multiple threads.
     *
     * Be aware this method needs be called before
     * {@link EpollDatagramChannel#bind(java.net.SocketAddress)} to have any
     * affect.
     */
    public EpollDatagramChannelConfig setReusePort(boolean reusePort)
    {
        try
        {
            Native.setReusePort(datagramChannel.fd().intValue(),
                    reusePort ? 1 : 0);
            return this;
        }
        catch (IOException e)
        {
            throw new ChannelException(e);
        }
    }
}
